Vabiable-aie condenser



Matth 5, 1929.4 l.. l.. JONES VARIABLE AIR coNDENsER 1926 2 Sheets-Shee@ filed July 7 CIJ Patented Mar. 5, '1929.

LESTER' L. JONES, OF ORADELL, NEW JERSEY.

2 VARIABLE-AIR CONDENSER.

Application sied. :any t,

This invention relates to variable air condensers, and has special Vreference to the provision of improvemints in variable air condensers, of the multiple or gang type.

-As is well known,'multiple variable air condensers are employed in radio circuits for effecting the simultaneous tuning of a plurality of associated circuits, such condensers being now commonly employed in radio receiving circuits ot the so-called tuned radio "frequency type in which it is desired to simultaneously control the resonance or tuning of a pluralityot cascaded circuits.

To eiect the simultaneous adjustment or unicontrol of a plurality of tunable circuits, multiple condensers of various types have been'suggested, amongwhich the two most common forms are,r irst, the condenser construction in which the rotors are arranged coaxi'ally and operated by a single shafft, and

second, the typey of condenser construction in which the. condenser .units are mounted side by side and Aare coupled together by some Vmechanical means for effecting the simultaneous rotation of 'the rotor shafts.

` One oit the most diliicultproblems that has confronted the art in the designv of these multiple condensers, especially for sharply tunable radio receiving circuits is that of producing a resulting l condenser construction inV -which the condenser units are l matched'with the precision or exactne'ss required for producing simultaneous tuning of the circuits and particularly over the whole wave length range over which the radio receiving system is tunable. Numerous methods have been suggested or devised -r"orrsolving this problem, such as the provision of independently adjustable plates conncct'ed in circuit with the condensers or Vsmall adjustable condensers connected in circuit with'the tuning condensers etc.; but these, as Yfar Iam aware, have not proved successful in prat-tive.` Numerous factors met with in the manufacture and assembly aswell as in the continued use ofthe con-Y densers vitiate the results obtainable with the use' of thescf independently adjustable plates orcondensers; and the problems confronting the worker in thc-art are found to .increase with the number of condenser units which are desired V to be joined for simulta'neous operation. In spite of the suggested solutions, the most common way known in the art today of effecting the[enactA tuning 1926. Serial No. 120,947.

of the associated radio receiving circuits resides in producing independent adjustments ot the condenser units for effecting the refined setting thereof after ay coarse setting is obtained by a simultaneous adjustment.

.Y A prime desideratum of my present invention resides in the design and construction of a multiple gang condenser which may be manufactured and assembled especially by quantity production methods so that the condenser units are matched with that precision required for eliectingV the simultaneous tuning of sharply tuned radio receiving circuits, with the construction such u. i- 1 laat the condenser units and the assemoled condenser construction remain stable after extended periods orn service.

A still fur'her principal object of my present invention relates to the provision of single condenser units embodying a number of the features or advantages of the multif ple condenser construction.

To the accomplishment of the foregoing and such other objects as will hereinafter appear, my invention consists in the elements and their relation one to the other, as hereinafter more particularly described and sought to be defined in the claims; reference being had to the accompanying drawings which show the preferred embodiment of my invention, and in which: Fig. l is a top plan view ot' a multiple Vcondenser showing four units in gang arrangement and embodying the principles ot' my present invention,

Fig. 2 is a front elevational view thereof shown on an enlarged scale, l

Fig. 3 is a cross-sectional view thereof taken in the plane of the 'line 3 3, Fig. l,

Fig. l is a cross-sectional view thereof taken in the .plane of the line -/l-4, Fig. l,V

` Fig. 5 is a longitudinal fragmentary crosssectional view thereforc tahen in the pl ane olt the line 5h5, Fig. l',

Fig. 6 is a longitudinal cross-sectional view taken in the plano ot the line 6 6, Fig. 5 Iand' showing the same on a more enlarged scale, f

7 is an enlarged cross-sectional view of a compensating condenser employed with the multiple condenser-,taken in the plane of the 7 7, Fig. 6, and

8 is a view of the compensating condenser Vtaken in cross-section in the plane the l z 7.

vcondenser'units comprising a stator anda rotor designated respectively by s and/r with an Vexponent corresponding to that of the condenser unit of which it forms a part.`

`'lo carryoutthe principles of my invention, Idepart from theniethod now used of assembling the rotors and stators, which method consisted in connecting the rotors conductively on a common shaft and in insulating the stators of the independent condenser units from the frame and from each other; and Vin accordance with the principles of my invention, theV stat-ors .eL- st each comprising a stator plate set having a number of condenser.plates'fare mounted on the frame ain conductive connection therewith, while the rotors arf-1** each also comprising a rotor plateset having a plurality of plates arranged to interleave Vwith the stator plates are mounted on .the frame insulated there-` from and .from each other. Although the y .rotor units are thus-'mounted in independent insulated condition, theyv are connected together sothatthealigned rotor shafts thereof -are connected for rotation in unison allv operable bya single shaft. YVith this mode ofl assembly, as will become clearer hereinafter, each of the condenser units is in effect an independent Vcondenser unitfcapable .of independent,adjustment and therefore capable of being connected totlie'other con- .denseinnits and built ingang or assembled relation withoutV introducingl the difficulties fof support and. adjustment which were found incident to multiple Vc'ondensers built Y in accordance vwith the prior inode-of Vassembly.A Y

' 'es a second step in the carrying out of my invention, each vof the independently adjustable i orsis mountedY on thev supporting rcondenser frame in a mann i' tol edectually take up the radial and axial strains, each rrofthe rotor unitsbeing also so mounted as to permit of independent lateral and axial adjustments thereof, which adjustments are independent also for leach rotor unit, permittingV eachzof the condenser units to beset or 'adjusted in `the'assembling operation without affecting the adjustment of any other condenser unit, Aand permitting the building up of the .assembled Vcondensers in the manner specified. l

To kfacilitate the understanding ofthe method of inter-relating the condenser units,

Y I will first describe the, construction and mode of operation of one of the condenser units by referenceparticularly to Figs. 5

vand 6 of'v the drawings in which the con-'f denser unit C Vand the manner of mounting the same on the frame F, aswell as the manner of connecting the same to the condenser C2, are shown onan enlarged scale. Y

l VThe frame F comprises apluralityof longitudinal supportingrods, here four in number,i10, 11, 12j and 13 Vconnected together at their front ends by the pedestal supports 15 and 16 by means of the sciew bolts '17,'17 and similarly rconnected together at their rear ends l(see Figs. 1, 3 and Ll) by means of the pedestal supports 1S Vand 19. These longitudinal supporting rods are-also joined together at intermediate points by a plu- `rality of tie plates which form the bearing plates for the rotor units, as will be described 'hereii'iafteiz The plates ofthe rotor plate sets (9L-st are mounted in' the longitudinal supporting rods 10 to 14E, the rods i being suitably milledto receive portions of the stator plates in the manner shown particularly in Figs. 3, 4 and 6 of the-drawings.

The stator )late setsarearranved alternately on opposite sides ofthe condenser asseiny bly toY produce balanced construction,fand to this end the stator plates of the stator units ,5"l and ss'aie fixed to the lower pair of supporting rods l2 and 13, while the stator plates ofthe units's'l and 's4 are fixedto the upper pair of'longitudinal supporting rods 10 and 11, all as will ybe seen fromaconiparison of Figs. l andl 3 and Figs. 1 and l.

ReferrinoV now again jarticularl to rFi s.

'p .a Y L 5 and 6 or the drawings, each oi ,tne' rotor units suoli as'the rotor unit r comprises a Y shaft 2O carrying the pla-tes of the rotor unit,

which pla-tes are :fixed to the shaft in accoid- Y ance 'with any well-known method, such" shafts being milled, Ytor,example, to receive central portionsV of the plates in a manner shown particularly in Figs. 3 to 6 of the drawings. .The shaft 'Ois mounted Vfoi-rotation in oppositely positioned bearings gefn' erally designated as 52 the mounting being such that the shaft 2O isadjustable `aXj-A ially and valso:preferably laterallyfor radi-v allyrwith respect to said bearings. The means for mounting the rotor unit and the Vshaft thereof is,v moreover, such that allradiyal .and axial strains are taken vup and-so that the rotor unit mayA be insulated from the framegF fand frointhe other rotor units Vby f dielectrics presentingeN maximum amount of r strength rin each direction' withY aininimum amount of -.material`located in the dielectric -field. Y. Y, f

, Each of the bearings such as 17%,?? is preferably made in accordance 'withV the method disclosed in my copending vapplication Ser.

No. 111,073, filed `lli/lay 22,1926, so' as to render the saine entirely free from geheim or tunits` of the gang assembly.

play, each of the said bearings comprising a Vshaft portion designated by 2l with an exponent corresponding to the bearing of which it is a part, the shafty portion being provided with oppositely positioned steel cones designating as 22 fixed to the shaft portion and cooperating with corresponding cone ends of a bearing box 23 `fixed to a pair of plates 24 and 25, which plates are joined tothe longitudinal supporting rods iO- i3 and form tie plates as well as bearing supporting plates, these parts being-indicated by thev reference characters with exponents applied thereto corresponding to the bearings of which they form the parts. These tie plates 24 and 25 are received by suitable milled slots in the longitudinal sujiporting rods llll-i3 and similarly receive the' bearings such as b" and o2, as will be readily evident from a considration of Figs. 3, 4l and 6 of the drawings.

Each of the rotor units such as the rotor 1" is mounted in the bearings l) and b2 insulated t therefrom, the mounting including means for adjusting rthe rotor unit axially to .adjust the space. orzclearance between the rotor and stator plates and radially or laterally toy match the contours of said rotor and statorplates, this construction permitting the exact matching of the condenser The Yrotor mounting means comprises rotor supporting members disposed laterally of the rotor and connecting the same to the bearing supports at laterally vspaced points combined with axially disposed rotor spacing members which are'axially adjustable in the bearings for p redetermining the spacing between the plates, this comprising more specifically a pair of insulating plates 26 and 27 (designated with an exponentcorresponding to the eendenser` unit in whichr they form parts) made of `sheet dielectric and `joined to opposite ends ofthe rotor shaft, a pair of metallic plates 28 and 29 (with corresponding exponents) fixed tothe ends of the bearing shaft portions-such as 2l and 212, the said vplates being connected together at points spaced laterally of said shafts, the construction including a pair of stud insulators 30 and 3l (designated with similar exponents) fixed to opposite endsof the rotor shaft and engaged by adjustable screw studs such as the studs 32and 33v which. are threadedly adjustable in the shaft portions 2l and 212, the latterbeing suitably interiorly threaded to receive the said stud.. y Y` The insulating plates such as plates 2G and 27 are preferably fixed to the opposite ends of the shaft 2O by riveting the shaft ends onto .the plates and the conducting plates such as 28 and 29 are similarly fixed or attached to the bearing shafts by rivet- Ving the ends ofthe bearing shafts onto the said plates, allas clearly shown, for exa-nr ple, in Figs. 5, 6 ofthe drawings. An insulating pla-te is connected to a conducting plate at the points spaced from the rotor shafts by means of studs 34, 3a suitably riveted to one of said plates, which studs threadedly receive screw bolts 35, 35 engaging the other of said plates, all as clearly shown in Fig. 6 of the drawings. The apertures in the dielectric plates 26 and 27 which receive the screw bolts are preferably made enlarged as at 86 (see Fig. 6), this being provided so that the rotor unit may be adjusted radially in any direction with respect to the bearings so as to match up the contours between the rotor plates and the stator plates. By matching up the contours, it -will be appreciated that cach of the condenser units may be made to conform to a predetermined calibration curve,the radial adjustment taking care of the unavoidable accumulated errors found in manufacturing and assembling the plates and supports for the condenser units. The stud insulators such as 30 and 3l preferably are made of quartz and engage the adjusting studs 32 and 33 so that adjustment of the latter in the bearing shafts effects the axial spacing of the rotor plates. Y

By means of this construct-ion it will be seen that the radial and axial strains of the rotor are effectively taken up by the connecting plates and adjustable studs, the former defining the lateral or radial supporting means for the rotor and the latter delining the axial spacing and supporting .i eans therefor. It will be further seen thatra maximum amount of support-ing and operating strength is thus provided in both axial and radial directions with a minimum amount of insulating material, the sheet dielectric and stud insulators being, moreover, located in a dielectric field of low strength.

t will be further seen that each side of the rotor u'iay be independently adjusted in almost any direction producing a universal and flexible mounting for the saine, the Aradially arranged insulating material being axially flexible though radially rigid to effeet the desired result. Moreover, it will be apparent that each rotor unit is rendered independent of the other. rotor units so that a similar flexible mounting is provided for each rotor aud similar adjustnie is effected therefor.

T he manner in which the condenser units forming the assembly are'inter-relateifl to produce the aforementioned results will now become more evident. rlhe bearing 712 arranged intermediate the condenser units C and C2 is a bearing common to two cendcnser units; and adjacent ends adjacent` rotor shafts are independently adjusted and supported in the common bearing. Thus the forward end of the rotor is mounted on the hearing 52 by means of the I 262 and 282 connected ltogether by means of the statoi'sare firmlyV supported in .units he carried out any number of condenser units,.tlie1same being shown vemployed to: 'four condenserurits F ig. l of the drawings; and rete Aiig now to Fig. l of the drawin s, itvvwill be seen that the remainingcondonser units are interconnected by bearings l@ tzend hsupported in bearing and tie plates 2li and 25 designated with exponents correspondingto the bearings or which they forni parts, the con denser rotors being mounted or hung on these bearings in a manner similar to that heretofore described by means which are designated by corresponding reference characters. 4 Y

By'means of this constructioniall of the rotor' units may be operated in unison by the rotation of the iront projectingshaftV portion 21, rotation of the condenser rotors being limited to a semifrevolution by means of the stop'elements generally 'designated a 37. It `will .he `tura-her seen that all o he con denser frame F and that each of the rotors is flexibly mounted for independent adjust nient, although all of the rotors are connected for operation in unison. rlhe tie plates 242, 252 etc.l arranged intermediate Vadjacent condenser units are conductively integral with the condenser traine and there- `toi-e serve as a means for shieldingonecondenser unit trom the others.

The rotor sup- `porting platos suchvas platesy 29 and 282 also for similar reasons serve as shield plates, and these are preferably made ovalshaped as clearlyshown in Figs. v3 to 5. ot'

; the drawings., so as to embrace the whole sweep of the condenserI plates toeliectively shield one unit troni the n'eit, the oval shape being desired also'to Vmore readily facilitate assembly ci .the shaft and attached plates into'the stator frame. rlhe line joining the studs Bet is at anacute angle to the major axis o'lE an'oval supporting plate so to permit easyV asseinblyfof theparts and particularly the attachment ot tlieplates by the stud screws. iesii lily the rear end oic L mi@ cli isat-tached a leg bracket` 3S. l vithy the above-recited construction I 'Y have found that the individual condenser units Vot Vthe assembly ymay' be readily matched to produce the same calibration curves. and maybe operated in circuit to produce resonance ineharply tuned soldered,

with a connecting endl piece d6".

rss'emhly.isprovidedwwith a plate 88' circuits without necessitating the individual adjustments `ot the condenser iinitsV to obtain a line or sharp adjustment. I have found, `moreover7 that the adjusted values remain stable in operation and in continued service.

The and radial adjustments eiiected produce a condenser matching over the desired wave lengthrrange, and in order to effect an equalization oi' the n'iiniiiiumrcavpacities of' the condenser units lwhen' in connected circuit, l prefer to additionally prof vide compensating condensers which I' will now` describe. lt will he understood that in connected circuit the capacities orp the leads, the electron discharge tube-and coils vary Yfor the dil'lerent circuits; and l prefer to util'z'e the compensating c ,noenseis for equaliifig at the minimum setting ot the condens rs these circuit capacities.

@ne et the compensating condensers Yis shown vassociatedV with the condenser units C and the saine `is shownl particularly in 6 to 8 oi the drawings. This compencondenser comprises an insulating O toi-ming a support for the condenser ed to the lonvitudinal Y supporting ll and l2 positioned in milled slots rein the compensating condenser further `indire a Vhigh potential plate vel held to ears 42, e2' turned overY in corresponding ieinsulating support 470 by means ,of four notches inthe insulating piece 40,-. the high v potential'plate having at one end a tab 4 5 to which the spring lead 46 ot therotor is said plate being furtherV provided 'thehigh potentialplateiil and a conducting ypla-te 4? also supported inthe rods 11 and l2, there is provided a mica rectangle 48 `approXimately twenty mills thiclrwhichv is slipped bet-Ween the high potentialr plate 4l and the conducting plate 117, the latter being the ground plate. Y -Y Y The ground plate 47 is also supported in the rods ll and l2by means ot inilledfslcts and the difference between the slots holding theplates l() and if? should be just suiiicieiit to accommodate the plate ll and the mica Vpiece 48. Y Adjustment of the condenser is first very roughly by the insertion oi .the mica rectangle and final adjustment is made by pulling together the platesV e() and 47 byineans of a screw nut 49,'the opening inthe'platel surrouiidinglthe screw nut being preferably enlarged as shown. 'r-i'itjter making this adjustment a touch .of solderV may he' applied to the Vtace ofthe nutlQ. Thedinie-nsions of this compensator condenser are made preferably suchthat tlie'saine be Vadjusted between the Values ci `2O and 30 mmitds. Y

The inanner'oi making and assembling the gang multiple condenser of my present invention and the manyY advantages there-o Between Will in the' main be apparent from the above ldescription thereof. It Will be furtherapparent that a number of the advantages obtained in the building` ofmultiple ccndensers are also characteristic of the male ing of single or unitcondensers as shown, for example, in Fig. 6 of the drawings, and may be so utilized. It will be further appreciated that while I have shown and described my invention in the preferred form, many changes and modilications may be made in the structure described 'Without departing from the spirit of the invention, delined in the following claims.

I claim:

l. In a variable air condenser, a stator plate set-,a rotor plate set unit and a mounting means forrotatably supporting the rotor unit, saidmounting means including mechanism for adjusting the rotor unit axially to fix the spacing or clearance between the rotor and stator plates and for adjusting the rotor unit radially to matchthe contours of the rotor and stator plates.

2. In a variable air condenser, a stator plate set, a rotor' plate set unit and a mounting mea-ns vfor rotatably supporting the rotor unit, said mounting means including mechanism for adjusting the rotor unit axially to ix the spacing or clearance between the rot-or and stator plates and mechanism for inde pendently adjusting the rotor unit radially to match the contours ofthe rotor and stator plates.

3. In a variable air condenser, a frame, a stator plate set conductively mounted on said frame,a rotor plate set unit and a mounting means for insulatably supporting the rotor unit on said frame, saidmounting means including mechanism for adjusting the rotor unit axially to fixthe spacing or clearance between the rotor and stator plates and -for'adjusting the rotor unit radially to match the contours of the rotor and stator plates.

4. In a variable air condenser, a frame, a stator plate set conductively mounted on said frame, a rotor plate set unit anda mounting means for insulatably supporting the rotor unit on said frame, said mounting means including mechanism for adjusting the rotor unit axially tofix thespacing or clearance betiveenthe rotor and stator plates and mechanism for independently adjusting the rotor unit radially to match the contours of the rotor and stator plates.

5. Ina variable air condenser, a frame, a Istator plate set mounted on said frame, a rotor plate set-unit, bearings on opposite ends of said frame and means rotatably mounting said rotor unit in said bearings, said means comprising members for axially adjusting the rotor unit relative to said bearings and members for radially adjusting the rotor unit relative to Isaid bearings.

6. In a variable air condenser, a frame, a stator plate set mounted on said frame, a rotor plate set unit including a shaft, bearing-s in said'frame, and means rotatably mounting said rotor unit in said bearings, said means comprising rotor supporting members disposed laterally of said rotor shaft and connected to the bearings for supporting thereinv the rotor unit at laterally spaced points, and axially disposed rotor spacing members axially adjustable in said bearings for axially spacing and supporting the rotor unit therein.

7. In a variable air condenser, a` frame, a stator plate set mounted on said frame, a rotor plate set unit including a shaft, bearings in said frame, and m-eans rotatably mounting said rotor unit in said bearings, said means comprising axially flexible but radially rigid rotor supporting members disposed laterally of said rotor shaft and connected to the bearings for supporting therein the rotor unit at laterally spaced points, and axially disposed rotor spacing members axially adjustable in said bearings for axially spacing and supporting the rotor unit therein.

8. In a variable air condenser, a frame, a stator plate set mounted on said frame, a rotor plate set unit including a shaft, bearings in said frame, and means rotatably mounting said rotor unit in said bearings, said means comprising axially flexible but radially rigid rotor supporting insulating plate members disposed laterally of said rotor shalt and connected to the bearings for insulatably supporting therein the rotor unit at laterally spaced points, and stud insulators disposed axially of said rotor shaft and adjus'tably connected to said bearings for insulatably adjustably spacing and supportingthe rotor unit axially in said bearings. Y

9. In avvariable air condenser, a frame, a stator plate set mounted on said frame, a rotor plate set unit including a shaft, bearings in said'frame, and means rotatably mounting said rotor unit in said bearings, said means comprising members fixed to said bearings and shaft, extending laterally therefrom and connected together at points spaced laterally of said shaft, certain of said members being axially flexible though radially rigid, and axially disposed members engaging the rotor shaft and adjustable in said bearings for axially spacing and supporting the rotor unit therein.

10. In a variable air condenser, a frame, a stator plate set mounted on said frame, a rotor plate set unit including a shaft, fixed bearings in said frame, and means rotatably mounting said rotor unit in said bearings, said means comprising members' fixed to said bearings and shaft extending laterally therefrom and connected together at points spaced CII laterally of saidshaft,certain of said members-being laterally adjustable With respect mounting said rotorunit in said bearings,

said means comprising insulating plates fixed to said rotorY shaft, conducting plates fixed tothe bearing! shafts,- means connecting the platestogether'at points spaced laterally of said shafts, insulating` studs fixed to the rotor shaft,andstud members engaging theinsulating studs and threadedly adjustable in said bearing shafts.l 1

` Vl2. A multiple variable air condenser comprising a supporting metallic frame,'a plurality of stator plate sets mounted on said frame,`and conductively connected thereto, a plurality of independent coaxially arranged rotorplate set units cooperating with the stator plate sets, and meansconnecting the axially ali'nedy shafts of all the rotor units for rotation in unison, said means ini cluding mechanism for mounting the rotor units insulated from each other and from said frame. H A

'13. A multiple variable air condenser comprising a supporting metallic frame, a plurality of stator plate sets mounted on said frame: and' conductively connected thereto, a plurality of'independen-t coaxially arranged rotor plate set units cooperating With the stator plate sets, means connecting the axially alined shafts of all the rotor units Vfor rotation in. unison, said means including mechanism for mounting the rotorv units insulated from each other and from saidl frame, and means forl adjusting a rotor unit relative to a stator plate set.

14; A multiple variable aircondenser comprising a supporting metallic frame, a plurality of stator 'plate sets mounted on said frame and conductively connected thereto, a plurality ofV independent coaxially Y 'arranged rotor plate set units'cooperating Vwith thestator-plate sets, means connecting the axially alinedshafts of'alll the rotor units for rotation in unison, said means including mechanism vfor mounting the rotor unitsinsula'ted from each other and from said frame, and meansfor independently adjusting each of the rotorunits relative toits associated stator plate set.

15. A multiple variable air vcondenser comprising a supporting' frame, a plurality of stator plate sets mounted on said frame, a plurality of independent coaxially arranged rotor plate' set units cooperating Y with 'the stator plate sets, means-connecting betweenV and to match the contour of theY plates of the same andra stator plate set.

'16. A multiple variable air condenser comprising a supporting frame, a plurality of stator plate sets mounted on said frame, a plurality of independent coaxially arranged rotor vplate set units cooperating with the stator plate sets, means connectingV the axially alined shafts of all the rotor units Vfor vrotation in unison, said means including mechanism for mounting the rotor units insulated from each other and from said frame, and meansA for independently adjusting each of the rotor units with respect to its associated stator plate set both axially and radially.

17. YA multiple variable air condenser comprising a supporting metallic frame, a plurality of stator plate sets conductively mounted on saidffraine, a plurality of rotor plate set units cooperating Withthe stator plate ets and provided Wit-h coaxially arranged shafts, means'connecting the shafts of'all the rotor units for rotation in unison, said means including mechanism 'for adjusting a rotor unit relative to its associated stator plate set and independently of the other rotor units. y Y

18'. A multiple variable air `condenser comprising a supporting metallic frame, a plurality of stator plate sets .conductively mounted on said frame, a plurality of rotor plate set units cooperating With thel stator plate sets and provided With coaxially arranged shafts, means connecting the shafts of all the rotor units for rotation in unison, said means including mechanism for adjusting each of the rotor units axially independently of each other and relative to its associated stator plate set.V

19. A multiple variable air condenser comprising va supporting frame, aplurality of stator plate sets mounted on said frame, a plurality of rotorplate set units cooperating With the stator plate sets and providedl with coaxially arranged shafts, and means connecting the shafts of a pair of rotor units for rotation in unison, said meansccmprising a shaft intermediate the shafts of the .rotor units, andl means-mounting the rotor shafts in ,saidl common shaft for independentadjustment therein.

20. A multiple variable air condenser comprising a supporting frame, a plurality of stator plate sets mounted on said frame, a plurality of rotor plate setunitsk cooperating with the stator plate sets and provided with coaxially arranged shafts, and means connecting the shafts of `apair of rotor units for rotation in unison, said means comprising a shaft intermediate the shafts of the rotor units, and means insulatably mounting the rotor shafts in said common shaft for independent adjustment therein.

21. A multiple variable air condenser comprising a supporting frame, a plurality of stator )late sets mounted on'sa-id frame a plurality of rotor plate set units cooperating` with the stator plate sets and prvided with coaxially arranged shafts, and means connecting the shafts of a pair of rotor units for rotation in unison, said means comprising` a shaft intermediate the shafts of the rotor units, rotor supporting members disposed laterally of said shafts and connecting the common shaft to the rotor shafts so as to support the latter at laterally spaced points and axially disposed rotor spacing members independentlyT adjusted in said common shaft and engaging the rotor shafts for independently adjusting the rotor units axially wit-h respect to the associated stator plate sets. v f

22. A multiple variable air condenser comprising a supporting frame, a plurality of stator plate sets mounted on said frame, a plurality of rotor plate set units cooperating with the stator plate sets and provided with coaXially arranged shafts, means for mounting each of the rotor units including mechanism for adjusting each of the rotor units axially to X the spacing between the plates thereof and the plates of its associated stator and for adjusting the said rotor unit radially to match the contours of the rotor and stator plates, said mounting means including a common shaft intermediate adjacent stator units.

23. A multiple variable air condenser comprising' a supporting frame, a plurality of stator plate sets mounted on said frame and conductively integral therewith, a plurality of rotor plate set units cooperating with the stator plate sets and provided with coaxially arranged shafts, means connecting the rotor shafts for rotation in unison, said means including mechanism for mounting said rotor units insulated from said frame and from each other, and a shield plate arranged intermediate adjacent rotor units in conductive connection with said frame.

2l. A. multiple variable air condenser comprising a supporting frame, a plurality of :tator plate sets mounted on said frame and conductiyely integral therewith, a plurality ef rotor plate set units cooperating with the stator plate sets and provided with coaxially arranged shafts, means for connecting the rotor shafts for operation in unison, said means including mechanism for adjustably mounting each of said rotor units insulated from sain frame and from each other, said mounting mechanism including a shield plate arranged intermediate adjacent rotor units in conductive connection with said frame.

Signed at New York city, in the county of New York and State of New York, this lst day of July, A. D. 1926.

LESTER L. JONES. 

